Study On The Effects Of Oak On The Quality Of Dry Red Wines

The aim of this paper is to research the effect on adding different types of oak wood products into wines at different period during and after the fermentation.The red grapes variety Cabernet Sauvignon grapes were used and fermented in the same processing.6g/L different oak products were added to each sample of the first group at the beginning of fermentation, which were as follows:French medium-toasting oak powder(FMTP), French medium-toasting oak chips(FMTC), American medium-toasting oak chips(AMTC), blending of the AMTC and FMTP, French mild-toasting oak powder, and Chinese medium-toasting oak chips(CMTC). The wines were separated and stored after the fermentation. In the second group, the clarified wine which hasn’t been added any oak products during the fermentation were treated with the same6oak products as above mentioned for20days. All of the samples, physicochemical index was determined, sensory analysis was carried out, and the aroma compounds were analyzed by GC-MS.The sensory analysis resulted that both the two kinds of oak treatment (at different period)can bring the oak aroma to the wine, and make the flavor more complicated, but the specific organoleptic quality are different. The wines which were treated with oak during the fermentation have a better flavour, the oak aroma and the fruits are combining well, quite balanced and harmony. The oak treatment makes the wines more elegant and sweet, and there is no char taste in these wines. The wines which were treated with the same kind and same dosage of oak products appeared much more oak aroma, burnt flavour, separated, and unbalanced.Engenol, Guaiacol, Whisky Lactone, Vanillin,5-methyl furfural and Furfural were determined by GC-MS. Results indicated that different kind of oak and different process time can lead to different effect on aroma compounds in wines. Guaiacol could be extracted more efficiently which treated with oak during the fermentation, but content of the other5compounds raised after the fermentation.This study showed that the wine quality can be improved by the oak-treatment at different period of fermentation, the type of oak products and time of treatment was according to the wine flavour which needed.